基于图像测量的非饱和土p-s平面屈服轨迹研究

Yield locus of unsaturated soils on p-s plane based on digital image measurement method

运用数字图像测量方法,测量非饱和土试样的整体变形和试样受端部约束影响较小的中部1/3区域的变形.控制吸力的非饱和压实土各向等压试验结果表明,试样整体与中部1/3区域的比体积与平均净应力的试验关系曲线存在明显差异,据此确定的LC屈服曲线也有差别.无论是试验值还是数值模型预测的结果,都是测量试样整体变形所得的弹性区较大.

A new means of deformation measurement is introduced for unsaturated soil specimen in suction- controlled isotropic compression tests based on the digital image measurement method. The deformation of the whole unsaturated specimen and the middle section that is relatively little influenced by the end restraint can be measured by this method. Results of suction-controlled unsaturated compacted soil isotropic compression tests show that the v-p and v-lnp curves of the middle section are evidently different, that the LC locus of two kinds of model parameters are also different, and that the elastic range based on the whole specimen deformation is bigger than that on the middle section in both tests and model prediction.